Considering my sequence sources are varied, doing it at the controller is the only way. With one exception, they are all at 50%, 40%, or lower. That exception is set to 60% (Pixels facing straight up with a 360 degree view possible.)
One thing that really stands out is that the matrix based units (matrix, megatrees, etc.) really look great at these lower levels. Images that were washed out before are very viewable.